Processors within electronic devices draw differing amounts of power based on the number and type of tasks being performed. For example, a processor that is mostly idle utilizes less power than a processor that is executing at or near 100% utilization. Moreover, different applications may require different computational effort, and thus even if utilization is held constant, processors executing different applications may draw differing amounts of power.
Some processors have the ability to measure their internal silicon temperatures, and to request particular power supply voltages. When operating below predetermined silicon temperatures, a processor may request higher supply voltage (and increase clocking rate) such that the processor executes instructions more quickly. If silicon temperatures approach predetermined thresholds, the processor requests reduced supply voltage (and likewise decreases clocking frequency). However, even though silicon temperature may be well below the threshold, a processor may limit requested supply voltage (and clocking frequency) to ensure the power draw is within the limits of the voltage regulation circuitry.